This is a pair of very high precision lathes
What makes this/these machines so fascinating is the combination of when it was created, the machine requirements, and the entity they were created for. The machine was delivered in 1964. The requirements were that the machines be extremely precise: 5 microns spindle runout, which is still non-trivial for mechanical machines. Test machining on mild steel was required. (Remember that this is before the advent of broadly available computer systems) The customer was Union Carbide Nuclear Company, of Oak Ridge Tennessee. General Electric (GE) was somehow involved in the ordering chain, but the details are unclear.
Some oral history/anecdotes: Family recollections indicate these machines were destined for Hanford, Washington; one of the key items is that it was designed to be remotely operated, once installed.
At a guess, this/these machines were designed to machine radioactive materials, such as Uranium or Plutonium. They were hydraulically driven with remote controls, which makes them less susceptible to the effects of radiation on electrical/electronic systems.